The present invention is directed, in general, to a wiring apparatus and, more specifically, to an apparatus for increasing the surface area packing density of analog wiring in analog telephone junction boxes for multiple extension installations.
In many industrial sites, analog wiring is still used to provide telephone service to large areas with a single telephone line. Multiple extensions are required over the entire area in order to permit workers to readily make and receive telephone calls from anywhere in the work area. Such a system, of course, saves significantly in limiting the number of telephone lines needed to support a large work area, as billing is based upon the number of lines, not the number of telephones accessing the same line. Also, this system makes it possible for an incoming call to be routed to a worker without knowing the worker""s precise location within a large work area. The system also makes it easier for the calling party to reach the worker by dialing a single number for a worker that may be anywhere in a large work area. Also, by staying with analog phones, the much greater expense of cellular phones is avoided.
However, as any telephone installer will readily admit, the telephone junction boxes for a large number of analog telephones may be quite large, occupying several square feet of a wall. Typically, the incoming cable pair for each line is routed to a terminal bar inside the telephone junction box. Referring initially to FIG. 1, illustrated is a block diagram of a conventional analog telephone junction box 100 with an exploded view of a terminal block 120. The conventional analog telephone junction box 100 comprises terminal bars 110 made up of a row of terminal blocks 120. Each terminal block 120 in the illustrated embodiment comprises a plurality of connector pairs 122, each pair separated by an insulator post 124. A conventional terminal block 120 in common usage is the Anixter 110C Connecting Block, that will be generally referred to as a terminal block for this discussion. The connector pairs 122 comprise two one-wire push-to-couple contacts 122a, 122b on either side of an extension indicator post 125 that also serves as an insulator. The incoming cable pair 130a, 130b, representing a single telephone line, is looped successively above and below the series of extension indicator posts 125 in a serpentine manner.
Referring now to FIG. 2 with continuing reference to FIG. 1, illustrated is an enlarged plan view of a portion 2xe2x80x942 of the conventional terminal block 120 of FIG. 1. Each extension indicator post 125 is differently colored to designate a single extension telephone 140 of up to four extension telephones coupled to a single terminal block 120. The extension indicator post 125 further comprises upper and lower protuberances 126a, 126b. Individual cable pairs 145 to each extension phone 140 are coupled to the backplane 121 of the terminal bar 110 on either side of the colored extension indicator post 125. By looping each of the incoming wires on the same side of an extension indicator post 125, the push-to-couple connectors permit the cable pair 130 to be quickly connected to each of the extension phones 140 in order. The connector pairs 122 present a telephone serviceman with a simple means of coupling an incoming cable pair 130a, 130b to a plurality of extension telephones 140 already coupled to the terminal block 120 at the backplane 121. Cable pairs 145 to the extension telephones 140 are routed through cable races 150. The illustration shows that a large number of extension cable pairs 145 must be packed into the cable races 150. As a practical matter, by doing so the serpentine looping places the incoming cable pair 130 in front of the extension cable pairs 145. However, when an extension 140 has a problem, the extension cable pair 145 must be physically traced to its connection on the backplane 121, often disturbing the connections between the incoming cable pair 130 and the connector pairs 122.
Of course, when large numbers of telephone extensions are installed in a given work area, the dedicated wall area consumed with the junction box can be very high, easily on the order of tens of square feet. In some cases, this wall space in a commercial building could be put to better use.
Accordingly, what is needed in the art is an apparatus for increasing the wiring density of analog telephone wiring in a multiple extension junction box.
To address the above-discussed deficiencies of the prior art, the present invention provides a terminal block extension for use with a terminal block having electrical contacts and that is electrically coupled to a wiring system. In one embodiment, the terminal block comprises an insulating body having first and second coupling ends and a first conductor disposed within the insulating body having first and second conducting ends. The first coupling end is configured to mechanically couple to the terminal block. The second coupling end is configured to mechanically couple to another terminal block extension. The first conducting end is configured to couple to one of the electrical contacts. The second conducting end is configured to receive a first wire of the wiring system and cooperatively engage a first coupling end of another terminal block extension.
In an alternative embodiment, the insulating body has a first guide aperture therein configured to accept a first wire of the wiring system therein. The first conductor is movably coupled to the insulating body and is configured to pierce an insulation of the first wire as the terminal block extension is coupled to the terminal block.
The terminal block extension, in another embodiment, further comprises a second conductor disposed within the insulating body and having first and second conducting ends. The first conducting end of the second conductor is configured to couple to another one of the electrical contacts. The second conducting end of the second conductor is configured to receive a second wire of the wiring system and cooperatively engage a first coupling end of the another terminal block extension.
In yet another embodiment, the insulating body has a second guide aperture therein configured to accept a second wire of the wiring system therein. The second conductor is movably coupled to the insulating body. The second conductor is configured to pierce an insulation of the second wire as the terminal block extension is coupled to the terminal block.
The wiring system, in an embodiment to be described, is a telephone wiring system and the first and second wires are a telephone cable pair. In a specific aspect of this embodiment, the terminal block extension couples to an Anixter 110C connecting block.
The insulating body, in another embodiment, further comprises upper and lower attachment arms proximate the first coupling end and upper and lower attachment bosses proximate the second coupling end. In a further aspect, the upper attachment arm comprises an upper attachment detent and the lower attachment arm comprises a lower attachment detent. The upper and lower attachment detents are configured to couple to upper and lower protuberances of the terminal block. The upper and lower attachment detents, in yet another embodiment, are configured to cooperate with upper and lower attachment bosses of the another terminal block extension.
The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.